Brazilian police investigating alleged ticket touting at the Rio Olympics could ask UK authorities to start extradition proceedings against Ipswich Town owner Marcus Evans, a legal expert said last night.

However, it is not yet clear whether Mr Evans will face extradition to Brazil following the allegations that he has been involved in illegal ticket sales. His company says the allegations are “entirely without foundation’’.

Rio’s Civil Police Fraud Unit is reported to have issued a warrant for the arrest of Mr Evans, who was named by the Sunday Times Rich List as having a net worth of £765million earlier this year, more than former Beatle Sir Paul McCartney (worth £760m).

Three other executives at THG Sports – a corporate and sports hospitality company owned by the Marcus Evans Group – are also said to face arrest warrants.

Irishman Kevin Mallon, a director of THG Sports, has been detained in Rio for more than a week. He was arrested after police seized around 1,000 tickets for the Olympics in a hotel, some of which were part of the Irish allocation.

Officers were reported to have said the tickets were being sold illegally for up to £6,000 each.

PRO10, the Olympic Council of Ireland’s authorised ticket reseller (ATR), said it had legitimate customers for its tickets and Mr Mallon was acting as a collection agent for them in Rio, meeting clients.

A statement released by THG yesterday said: “We are extremely concerned by these charges.

“We have made absolutely clear that the allegations made against our colleague, Kevin Mallon, and ourselves are entirely without foundation.

“Pro10 have also made it absolutely clear that the tickets held by Kevin were on behalf of the Irish ATR and were held for collection by Pro10 clients in Rio.

“Having tickets on the ground for collection is standard practice for an ATR during games time.

“As has been reiterated on several occasions, at no time did Kevin Mallon sell or seek to sell tickets for the Rio Olympic games. The tickets that he held were authorised tickets held on behalf of clients of the authorised ticket reseller and he was acting as the collection point for the authorised ticket reseller’s customers.

“It is our understanding that all of these tickets are sold by the ATR at face value plus the mark-ups allowed under the agreements with ROCOG [Rio 2016 Organising Committee for the Olympic and Paralympic Games].

“Our Brazilian lawyers have advised us that there is no evidence to support these allegations, as indeed there is not, and we shall be vigorously defending all charges that have been brought. It appears that ROCOG and the local authorities have an agenda to impede the legitimate activities of THG in order to support the activities of their locally-approved hospitality provider.”

Robert Roscoe, solicitor with London law firm Victor Lissack Roscoe & Coleman, said if police in Rio de Janeiro can provide sufficient evidence against Mr Evans he could face extradition.

He said: “The general rule is that it must be an imprisonable offence of up to six or 12 months or more.

“If he’s not in Brazil, they will make a request to the extradition squad at Scotland Yard.

“They will explain what offence they allege he has committed, what evidence they have in support of it and they will say to the UK police if you see this man can you arrest him?

“If extradition is successful, it can be appealed. One would expect him to get bail on conditions such as surrendering his passport, wearing an electronic tag and reporting to police.”