AP – Former senior English policeman Jeff Rees is retiring after more than four years in charge of tennis’ anti-corruption group, with former fellow officer Nigel Willerton to replace him on January 1.

The Tennis Integrity Unit (TIU), which announced the changes on Monday, hired Rees as director in August 2008 after he helped to review possible match-fixing in professional tennis.

A former Detective Chief Superintendent with the Metropolitan Police in London, he was awarded the Queen’s Police Medal in 2000. Rees was also chief investigator of the International Cricket Council’s Anti-Corruption and Security Unit for eight years before turning his focus to tennis.

The ATP and WTA tours, the International Tennis Federation and the Grand Slam Committee formed the TIU after a series of player suspensions for betting on matches and a gambling investigation into a match involving Russian Nikolay Davydenko.

Rees was appointed by the governing authorities of tennis to establish the unit as a dedicated body to protect the sport from threats posed by gambling-related corruption. During his four-year tenure, he oversaw the introduction of comprehensive player education and training initiatives, together with the implementation of anti-corruption protocols in tournament situations.

The introduction of the Uniform Tennis Anti-Corruption Program, one of the most stringent anti-corruption codes in professional sport, was another significant landmark.

Under the code, investigations were carried out which resulted in five players and a manager being disciplined. Two players were banned from tennis for life – Serbian David Savic and Austria’s Daniel Koellerer.

Willerton has been a TIU investigator since June 2010. He was a senior officer with the Metropolitan Police, and his 30 years with the Force were spent investigating major crimes and complex criminal cases.

“Jeff Rees has provided tennis with exceptional leadership and guidance over the past four years and we pay tribute to the outstanding contribution he has made in protecting the sport from those who would seek to corrupt it,” said Philip Brook, 2012 Chairman of the Tennis Integrity Board.

“In saying farewell to Jeff, we welcome Nigel Willerton as Director of Integrity, confident that he will provide the continuity of operation so important to the sport. Nigel is already well known and respected by players and officials throughout tennis and will ensure a seamless transition of leadership takes place in this crucial role.”