A leading human rights group accused the Premier League last night of showing a “shocking lack of interest” in ethical standards for sanctioning Thaksin Shinawatra’s controversial takeover of Manchester City.

Brad Adams, the executive director of the Asia division of Human Rights Watch (HRW), branded Thaksin a “human rights abuser of the worst kind” who should not have passed the League’s Fit and Proper Persons Test (FAPPT) and claimed that the former Prime Minister of Thailand’s £81.6 million buyout of City would “end in tears” sooner or later.

The accusations drew a robust defence from the League, City and Thaksin, whose lawyer said that the allegations of “widespread, serious and systematic” human rights abuses against his client were completely unfounded.

HRW’s concerns about Thaksin, which were outlined in a letter to the League yesterday, were echoed by Amnesty International.

Speaking to The Times, Adams, who claimed that the League had not made “the slightest bit of effort” to contact HRW, said: “I feel sorry for Manchester City supporters. I know they want to be able to buy the best players and for their team to succeed, but they don’t want this man’s [Thaksin’s] money to buy players and I don’t think he is in it for the long haul. This will end in tears for them and they would have been better off having someone else buy the club.”

Thaksin was ousted from office in a bloodless military coup last September, but his takeover of City last month continues to be overshadowed by accusations that, during his five years in office from 2001 to 2006, he presided over human rights violations.

HRW claims that the most disturbing of these came during the notorious “war on drugs” when more than 2,275 people were killed during a three-month period at the beginning of February 2003.

The next year, the US State Department reported that Thailand’s human rights record had “worsened with regard to extrajudicial killings and arbitrary arrests”, while the United Nations was said to have expressed deep concerns about the high number of deaths. HRW also alleges that Thaksin’s “brutal” attempts to suppress an insurgency in the south of Thailand led to the deaths of hundreds of ethnic Malay Muslims.

“Our research and that of other credible organisations shows that Mr Thaksin’s time in office was characterised by numerous extrajudicial executions, ‘disappearances’, illegal abductions, arbitrary detentions, torture and other mistreatment of persons and attacks on media freedoms,” Adams wrote in his letter to the League.

“Based on his record, Mr Thaksin does not appear to us to be ‘fit and proper’ under any reasonable definition of that term. His past actions should lead to him being subjected to investigations by impartial police and prosecutors, not welcomed into the club of owners of the most popular football league in the world.”

The allegations were strenuously denied by the lawyer of Thaksin, who also contests a series of corruption charges brought against him by the unelected Thai government. “The civil and human rights charges against him have never been proven,” Noppadol Pattama said. “My client deserves to be treated as an innocent man until proven guilty. I hope Manchester City fans and British people are fair-minded. They should suspend their judgment before deciding Thaksin is not fit.”

In a letter back to Adams, Richard Scudamore, the League’s chief executive, defended the FAPPT, which effectively prevents people who have been convicted of criminal offences, such as fraud or money laundering, from owning or becoming a director of a club, and pointed out that, on such matters as human rights abuses, the organisation is guided by the Government.

“The issues that you raise are extremely important, so much so that they fall to the UK Government, statutory authorities and the European Union to consider,” Scudamore wrote. “We would presume that you have presented any evidence that you believe is relevant to those authorities.”

Extreme owners

Luciano Gaucci Perugia’s “Chairman Gau” signed Al Saadi Gaddafi, the son of the Libyan dictator, who was described by an Italian paper as “twice as slow as slow itself”. He then attempted to sign a Sweden international – Hanna Ljungberg, a star of women’s football. He also tried to dismiss Ahn Jung Hwan because the South Korea forward scored against Italy in the 2002 World Cup finals.

Robert Maxwell His money propelled Oxford United to the top flight, but he alienated Oxford and Reading fans by attempting to merge the clubs to create Thames Valley Royals. Then he headed for Derby County, leaving Oxford heavily in debt and with his son, Kevin, in charge.

Jesús Gil The former mayor of Marbella, who died in 2004, was a demanding owner of Atlético Madrid. He went through 39 managers in 17 years in charge. After one poor performance, he said on radio that he hoped the team would die in a plane crash.

— Words by Tom Dart