A Co Tyrone teenager who took his own life after being duped into sending intimate photos online was subject to a "relentless" blackmail bid by a Nigerian gang, his parents have said.

Gerard and Teresa Hughes said their 17-year-old son Ronan killed himself only hours after learning the criminals had followed through with a threat to send the images to one of his Facebook friends unless he paid them £3,300.

The heartbroken mother and father, from Clonoe near Coalisland in Co Tyrone, have also criticised the police's response when they reported the blackmail plot three days before his death earlier this month.

The couple said their "quiet, happy-go-lucky" son had been tricked into sending images on a social network site after receiving pictures of a girl.

Mrs Hughes said her son, a pupil at St Joseph's Grammar School in Donaghmore, confided to her near midnight three days before he died.

"He came to me and said 'I'm in trouble here'," she said in an interview with the Irish News daily newspaper.

"He gave me his phone. They were looking for more than £3,000 for an image he had posted and told him they were going to show it to all his friends. They had sent him a list of all his Facebook friends. He texted them back to say 'but I'm only 17'."

Mr Hughes brought his son to a PSNI station at Dungannon immediately, but he said there was only one officer on duty at that time of the night and he said there was not a lot he could do.

"I knew Ronan was looking for help and I told him (the officer) that all my son wanted is for these images not to be posted," he told the paper.

"He told us that he couldn't guarantee that. For Ronan, it was totally dismissive. If the police had given Ronan reassurance and said 'we'll contact IT experts, we'll close this down, we'll stop that', Ronan would still be here today. That's why he came to us. He wanted help."

The couple brought their son back to police the next day and spent a number of hours with officers but said they did not hear anything back over the next couple of days.

On the day of his death, Mrs Hughes said Ronan called her to say a friend had contacted him to say she had received a link containing images, but she had not opened them.

Mr Hughes left work early to go home amid concerns how his son might react.

When he arrived he found notes on the kitchen table and then discovered his son's body in a field behind their home.

"The biggest point we want to get across is how naive parents are in relation to social media," he said.

"There is no point in a parent taking a phone off a child when they don't know what they are doing themselves or how to access the technology themselves."

Mrs Hughes said she and her husband felt it was important to speak out.

"We decided to speak out as this is something that could have been prevented," she said.

"A child with mental illness maybe can't be stopped from taking their own life. But to think that Ronan was living life to the full and then all of a sudden something like this can pop up and take his life...that's why we had to act.

"We want there to be changes so if a child out there is being bullied online they can go to the police or other authorities with their concerns. We don't want another family to go through what we've gone through."

The PSNI said it hoped to meet the Hughes family to discuss their concerns about its handling of the case.

Detective Chief Superintendent Brian Hanna said: "This is a tragic case and our sympathies go to Ronan's family. We acknowledge the concerns the family have raised and hope to meet with them in the coming days to further discuss these issues."

He said the Police Ombudsman for Northern Ireland was best placed to deal with any complaints in relation to police actions.

The officer added: "Our enquiries are continuing into what will be a complex and protracted investigation and we will keep the family informed of any progress as appropriate.

"In recent days, there has been a great deal of conversation about the steps young people, and indeed everyone, should take to stay safe online and I would urge anyone who has experienced anything of a similar nature or has received any inappropriate images or links to contact police or tell a trusted adult.

"We all deserve to be able to use the internet to learn, explore and connect with each other. But all of us need to be aware of the risks involved in doing so, especially on social media."

He urged people to check www.getsafeonline.org for advice and information on how to stay safe online.

Facebook said it did not comment on individual cases.