Nigerian forward Emmanuel Emenike is surrounded by policemen as he arrives a courthouse in Istanbul July 6, 2011. [Photo/Agencies]

ISTANBUL - A Turkish court jailed 15 more people, including top soccer club executives, pending trial on Thursday as part of a major match-fixing investigation which the prime minister said is staining the country's image.

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Three executives of champions Fenerbahce, the chairman of Sivasspor and coach of Eskisehirspor were among the 15 sent to jail on the orders of an Istanbul court, state-run Anatolian news agency reported.

A total of 22 have now been jailed after seven were sent to Metris jail in Istanbul overnight.

The investigation has thrown preparations for the new season into disarray just a month before kick-off and the Turkish Football Federation is expected to act soon in response to the allegations without waiting for the outcome of the case.

Among possible sanctions are exclusion from competitions, relegation to a lower division and potentially the loss of tens of millions of dollars in income. Any individuals convicted of match-fixing could face lengthy prison sentences.

Shares in major Istanbul club Fenerbahce, which won the league for a record 18th time last season, have lost a third of their value since news of the police raids emerged.

Istanbul police headquarters said in a statement on Wednesday it had seized eight unlicensed guns in the raids after a probe launched in December produced evidence of match-fixing in 19 games in the first and second divisions.

It also revealed a criminal gang stole and sold on questions in a football federation examination in March and had threatened players to force them to forego earnings.

'Staining image'

Some 22 people have so far been jailed pending trial, while 27 have been released, out of 61 people detained in raids launched early on Sunday. Another 11 were due to face the court on Thursday after questioning at police headquarters.

The most high-profile detainee, Fenerbahce Chairman Aziz Yildirim, was being treated in hospital for suspected heart problems and will face prosecutors when he is discharged.

Among others in jail are Sivasspor's goalkeeper, a former international striker, and the former chairmen of Diyarbakirspor and Giresunspor.

Prime Minister Tayyip Erdogan, himself a Fenerbahce fan, has called for a rapid and just outcome to the investigation, saying the affair was staining the country's image internationally.

European soccer's governing body UEFA has set a deadline of July 15 for confirmation of the team taking part in the third Champions League qualifying round. Trabzonspor were runners-up to Fenerbahce in the league and would normally take that place.

Police launched raids in 15 provinces across Turkey on Sunday, searching club premises and detaining players and administrators in connection with the scandal.

Turkish media have cited allegations in police reports such as a striker being offered money to not score in one game, a goalkeeper deliberately failing to prevent a goal and a club requesting a particular referee for a key derby.

Fenerbahce has denied involvement in any wrongdoing.