A sex tape reportedly featuring professional British boxer Amir Khan has leaked online. The X-rated video shows a man – believed to be the boxer – performing sexual acts on himself during a conversation with a woman on Skype.

It is also alleged that the woman – believed to be from the US state of Arizona – and the Olympic boxer had a fling in 2010 before he married Faryal Makhdoom in 2013.

"This is a mortifying moment for Amir," a source told the Sun. "He's a Muslim boxer and his personal life is under the microscope right now, so the timing couldn't be worse."

"There had been rumours about these videos for years but now anyone who wants to view them on the internet for free can do so."

According to reports, there are three more X-rated videos of the boxer. Khan's representatives have not confirmed or denied the reports.

The news of the sex tape comes at a difficult time in Khan's life as he has been embroiled in a public feud between his wife and family for the past few months.

The feud between Makhdoom and Khan's family was exposed after his wife accused her husband's family of bullying her in post she shared on social media. Khan's parents then had accused Makhdoom of making up the claims.

In a recent interview, Makhdoom said her many social media outbursts about her husband's family were because of "anger that's built up over the years".

"They have been so unkind. I was in Pakistan with Amir's family when his brother tweeted: 'Michael Jackson isn't dead. He lives with us.' He was trying to say I'd had plastic surgery. I was pregnant with our daughter, who's now two, at the time. Can you imagine what it was like being in the same house with him when he was saying that?" Makhdoom had said.

"She went on to claim the very insular family felt threatened by her, an independent part-time model who owns her own cosmetic company, because they feared she would take Khan away."

"Every single one of them is married to a cousin or a relative. Amir's sister [Tabinda] is married to a relative from the village. Amir's brother's [Haroon] marriage was arranged with a relative from the same village.

"But Amir picked me because he fell in love with me. I was the first outsider, and asking me to marry him was the first big decision he made for himself. I think there was jealousy. He sent me so many gifts. I believe they couldn't accept Amir had found someone who might take him away from them."