Watched by horrified holidaymakers on a sun-drenched beach, a police speedboat carries the body of a drowned migrant into a pretty Spanish tourist port.

The 30-year-old Algerian was shipwrecked in perilous seas when he set out, like hundreds of others, on an armada of rickety craft from North Africa to Europe.

He was tragically unlucky. Last week, 1,025 migrants arrived illegally on the Andalusia coast, where millions of Britons holiday each year in the famous Costa resorts. Every day, more come on what is now the fastest-growing migrant sea route from Africa to Europe.

In a distressing scene, the drowned Algerian in a body bag was dumped on the quayside at the port of Carboneras by police wearing white forensic suits and masks. It was just a few feet from 20 tourists, including Britons, climbing aboard a party cruiser for a late afternoon sail to watch dolphins at play off the coast.

Police recovered the body of an Algerian migrant and carried the man into a pretty Spanish tourist port

The coastguard boat Guardamar Polimnia brought in migrants who had just been rescued off the North African coast

A large number of migrants were rescued off the North African coast and into Almeria, Spain

Christofe, the 56-year-old owner of a local cafe overlooking Carboneras beach, saw the body brought in.

'Two others from the same shipwrecked boat were washed up here on the sand 50 yards away yesterday,' he said, referring to an eight-year-old boy and a man of 20 from Algeria.

Of course, we're all tragically familiar with pictures of overloaded boats ferrying people from Libya to Italy. Indeed, nearly 9,000 migrants have been rescued from vessels heading for Italy since Saturday.

The majority of the 83,000 migrants who arrived illegally in Europe by sea this year took this route, with more than 2,000 drowning during the crossing, according to official United Nations figures.

But as I have discovered, there is a new route, from Africa to Southern Spain, where migrants are arriving in increasing numbers on busy holiday beaches.

Since the beginning of this year, 5,082 have reached the 250-mile-long Andalusian coastline stretching from Cadiz, past Gibraltar to the Carboneras port resort.

According to Spanish coastguards, between 5,000 and 10,000 more migrants — mainly from impoverished sub-Saharan nations — today wait in Morocco to make the same illegal trip, helped by people-trafficking gangs who charge them £1,300 each for a place on a 'patera', or small boat.

Javier Pajaron, security correspondent of regional newspaper Voice Of Almeria, has watched the crisis develop this year.

He says: 'Without doubt, most are economic migrants and not refugees. They are looking for a better life. Many never get deported, but just disappear into the black economy.'

On the front line of this new sea crossing are Spanish coastguards, who race out of Andalusian ports to save migrants when their boats run into trouble.

Around 9,000 migrants have been rescued in the Mediterranean Sea and last week 1,025 migrants arrived illegally in Andalusia

Migrants had to be rescued by the coastguard after they had left North Africa together

A police speedboat carried the body of a drowned migrant into the Spanish resort of Almeria

In the booming resort town of Almeria, where 100,000 British holidaymakers flew in last month, Miguel Parcha is captain of an eight-man, 32-metre rescue vessel, the Guardamar Polimnia.

The crew has brought hundreds to safety after answering SOS calls from migrants at sea.

Under controversial EU rules, any vessel leaving Morocco and reaching international waters (starting 12 miles off the coast) must be helped by Spain because it's the nearest country.

As Captain Parcha says: 'The migrants know we will rescue them if they run into difficulties when they set off from Morocco. That is a fact. We do our work because otherwise they will die.'

On board the Polimnia in Almeria port, I was able to see how every wall of the cabin is plastered with photos taken by the crew of migrants they have saved. There are pictures of children, women and many, many young men.

'The children cry at first when we rescue them because they are traumatised,' says 57-year-old Captain Parcha. 'Then, when we bring them on board and they know they are safe, they laugh.

Police officers helped transport the body of the Algerian migrant who was found in the water

The coastguard (left) helped bring in migrants who had just been rescued close to the North African coast

Migrants were waiting to get off the boat after being rescued by the coastguard when they got into trouble

'One six-year-old girl called Happiness had been raped on her long journey to Morocco from sub-Saharan Africa. She was very solemn. We wrapped her in a blanket and gave her sweets, and finally we saw her start to smile.'

Captain Parcha and his crew reject the notion that by rescuing migrants they are effectively running a 'taxi service' to Europe, helping people-traffickers who operate with near-impunity in Morocco and Algeria.

Newly arrived migrants undergo identity checks while their asylum claims are considered and a decision made about whether or not they should be deported back to their home nation.

When the migrants are brought into the Polimnia's home port of Almeria, they walk straight to a reception centre — a long, low building hidden behind gates on the quayside — for initial registration.

Under Spanish immigration rules, within 42 hours they must be taken to a migrant internment camp for further questioning, and a decision made about whether they can claim asylum or must be listed for deportation.

However, many deliberately destroy or throw away their identity papers before they sail, to avoid being returned to their country of origin.

The law decrees that migrants cannot be kept in the internment camps for more than 60 days. After that, they have to be freed.

Those without permission to claim asylum receive a government document stating they are 'due for deportation' to their home countries. However, most simply disappear and are never removed.

Desperate women and girls often turn to back-street prostitution. The men sell trinkets on the beach or become black-market labourers in the giant greenhouses which litter the coast, where fruit and vegetables are grown for European supermarkets.

The illegals have to find work not only to survive (the state pays benefits only to asylum seekers) but also because they owe a vast sum of money to the trafficking gangs for their place on a boat.

In a sophisticated enterprise, the gang members — operating both in Spain and across Africa — stay in touch with migrants in person, by mobile phone or social media, extorting the cash by threatening to harm their families back home.

These debts can take years to clear. As Almeria charity worker Juan Mirelles explained: 'They arrive penniless, so they have to earn money to refund the fare to traffickers and to avoid starving.'

In Carboneras on carnival day I meet Fatima, a 39-year-old mother-of-three who is selling Moroccan-made baskets outside busy promenade restaurants. She sits on a wall under a tree, her youngest son, Mohammed, asleep in a pushchair beside her.

A group of migrants were photographed on an inflatable boat close to the shore after being rescued

Some of the migrants on the boat put their arms up in the air after being rescued close to Spain

They had bottles of water after being rescued by the coastguard boat Guardamar Polimnia

Fatima was born in Senegal and came to Spain by boat.

'I make a living this way,' she says, looking exhausted at 9pm. 'There are a lot of people from my country in Spain, because there is no money for us at home.'

I wonder — despite Senegal's poverty — why she and thousands of others from Islamic countries choose to come to Spain, a deeply Christian nation with a painful history of Muslim conquest which is still taught to children in schools.

In Fatima's case, without doubt, it is a simple and understandable economic imperative to try to make a better life for her family.

But there are increasing fears among European intelligence agencies that hiding among the migrants on the hundreds of 'pateras' are ISIS terrorists coming into Spain undercover.

In a terrifying twist, the trafficking trade itself is believed increasingly to be run by ISIS terrorists with links to the gangs running migrant boats out of Morocco. In turn, the handsome profits are funnelled towards the terror group. Andalusia was occupied by Muslims (known as the Moors) from 711 to 1492. After that, the Christian re-conquest of Spain took place, during which 100,000 Muslims were killed.

Islamic State believes Andalusia — and much of Spain — should still belong to them. ISIS declared in an official statement last year: 'Spain has for centuries done everything to destroy the Koran.'

It called on jihadists to seize control of the country. An ISIS video crowed: 'Spain is the land of our forefathers, and we are going to take it back with the power of Allah.'

The scenario Islamic State dreams of has chilling echoes of the recent past. In 2010, just before his regime's collapse, Libyan dictator Colonel Gaddafi demanded £4 billion a year from the EU to halt the flow of migrants from the North African coast.

Gaddafi threatened to 'turn Europe black' and send in terrorists, too, if he did not get the money, which was refused.

There are now fears that ISIS has adopted a similar strategy, and plans to overwhelm Europe by flooding it with migrants.

Frontex, the EU's external border control agency, estimates that millions of people from sub-Saharan and Arab nations are preparing to leave for Europe from the North African coast.

The problem is so huge that, last week, the British Government announced it is to spend £75 million of the controversial foreign aid budget on trying to send home migrants before they set out from North Africa. A three-year scheme to stem the crossings will include giving them free flights back to their own African nations.

Anthony Glees, director of the Centre for Security and Intelligence Studies at the University of Buckingham, has described Spain as a potential jihadist hot spot, with the holiday resorts being particularly vulnerable.

'They are a magnet for those who want to harm tourists,' he said. Meanwhile, the police in Almeria and along this coastline struggle to cope with the huge influx.

One officer warned in a national newspaper last week that bringing in the drowned bodies (of which there are many) and ferrying the rescued to deportation centres means the police are short of officers to work on 'countering Islamic terrorism' in Spain.

Like Professor Glees, the Spanish authorities say this is a 'hot point' for jihadis, who hide up and train in the coastal province, planning attacks on Europe.

But, for now, it is the migrant numbers that are worrying the locals most.

Maria Dolores Valencia, general secretary of the United Syndicate of Police, said: 'We have warned our government that many more migrants will arrive this summer, when the seas are calm and with their own countries in crisis.'

Jose Antonio Alcarez, spokesman for the Spanish Police Federation, told the Mail: 'We have a huge problem. We just can't deal with the migrant numbers. If we don't get more police to help, we will not be able to control the streets in Andalusia this summer.'

At a primary school in a town along the coast from Almeria, I watched as migrant families, mothers in hijabs and fathers with beards and sandals, waited to pick up their children.

And I saw young Africans, on shiny new charity bikes, pedalling along the coastal roads.

Back in Almeria, on a baking hot evening, I stood on the coast road and watched Captain Parcha's boat bring 48 more migrants into the port after rescuing them at sea.

On an adjoining beach, Spanish families mixed with holidaymakers as the bright red vessel, full of waving migrants on the deck, raced in. Two local boys of about 11 standing near me saw the boat arrive, too.

'The Moors are coming again,' one remarked to the other, and the pair of them laughed.

It was a childish joke, made without hostility. But if these migrants continue to arrive in such numbers, there must be a fear that ancient divisions will begin to rear their ugly head once more.