A billionaire suspected of helping fuel an African civil war by masterminding illegal shipments of AK-47s, missile launchers and tanks from the comfort of his Ibiza mansion would threaten anyone who crossed him with the words, “I will put you in a glass jar”, it has been claimed.

Pierre Konrad Dadak reportedly spent hundreds of thousands of euros turning his Ibiza mansion, with a fleet of supercars in the garage, into a fortress. But when it came for paying for a 12,000-euro (£10,000) specially reinforced glass shower door, Mr Dadak is said to have refused to pay the labour costs.

The Spanish news site El Español reported that the builder decided not being paid was preferable to ending up inside a glass jar.

The news site also reported that police suspect that Mr Dadak has been involved in numerous arms shipments to factions in South Sudan, where 10,000 civilians have so far been killed in a civil war that began in 2013. Investigators reportedly found an email in which Dadak offered to smuggle 200,000 Kalashnikovs, as well as rocket launchers and tanks, into the troubled East African country.

Mr Dadak is now in custody, suspected of arms trafficking, and Europol has issued a statement declaring: “Several members of the crime network were arrested. They are suspected of offences related to organised property crime, extortion, money-laundering, fraud, bribery and disclosure of official secrets.”

In a case that seems to echo the fictional plot of the recent mini-series The Night Manager, in which Tom Hiddleston’s character infiltrates an arms-trafficking ring run from a mansion on the Spanish island of Majorca by Hugh Laurie’s Richard Onslow, Mr Dadak was arrested in a dawn raid on 14 July.

After armed Spanish police subdued his bodyguards, Mr Dadak reportedly spent 30 minutes holed up in the mansion’s panic room before being captured as he tried to escape through a window.

Among those reportedly arrested with him was his ex-partner Kateryna Dirgina, a Ukrainian model.

The arrests, which coincided with simultaneous searches of companies in Germany and Switzerland, are thought to have been the culmination of a four-year international investigation.

Mr Dadak, a former Polish army officer, is said to have arrived in Ibiza – a party island renowned for its nightclubs and visited by 700,000 Britons every year – in 2011.

In what appears to have been an elaborate ruse to protect himself from scrutiny, the dual French-Polish national acquired a diplomatic passport from the West African state of Guinea-Bissau. He reportedly did this by promising to make large investments in the country.

It is thought that when the promised investments failed to materialise, the Guinea-Bissau authorities revoked his diplomatic privilege.

By that time, however, Mr Dadak had put a plaque up outside his Ibiza mansion, declaring it a consular residence owned by Guinea-Bissau, and therefore immune – along with the Lamborghinis and Ferraris parked there – from being searched by the Spanish police.

It is understood, however, that Mr Dadak soon drew attention to himself with his extravagant lifestyle.

El Español reported that despite having no obvious means of acquiring vast wealth, Mr Dadak had his own private jet and dined regularly at Ibiza’s Blue Marlin beachside restaurant, which has its own water taxi service to take diners to and from their yachts.

The Night Manager starred, from left, Hugh Laurie, Tom Hiddleston, Elizabeth Debicki, Olivia Colman and Tom Hollander (Mitch Jenkins/BBC)

It was reported that wherever he went, he was accompanied by an entourage of armed bodyguards. His business cards, meanwhile, allegedly declared him to be the “president shareholder” of a Warsaw-based company.

El Español also claimed that this year, members of Marseille’s notorious Barresi clan paid for him to enjoy his 40th birthday party in France.

In what was alleged to be a sign of both Mr Dadak’s links to organised crime and his uncompromising attitude to those who upset him, a Spanish police spokesperson was quoted as saying he once hired a Dutch criminal gang to go to Marbella to collect a debt of four million euros (£3.35m.)

After his arrest, the Europol statement, which did not name Mr Dadak, alleged: “By piecing together information gathered internationally, law enforcement authorities and Europol specialists discovered that the suspect had supplied firearms to several crime networks in Europe.

“Moreover, investigations showed that he supplied significant amounts of weaponry to an African country, estimated at some 200,000 Kalashnikov AK-47 assault rifles, missile launchers and tanks, via Polish companies he controlled.

“The investigation continues to identify eventual international links, further to those with Belgium, France, Germany, The Netherlands, Poland, Latvia, the UK and the US.”