* Opposition sees bid to quash graft inquiry
* Law seen as bid to limit influence of Islamic cleric
* Erdogan accuses cleric of conspiring with "faked recordings" (Adds appeal turned back for technical reasons)
By Gulsen Solaker
ANKARA, Feb 28 (Reuters) - Turkey's main opposition party asked the top court on Friday to overturn a law tightening government control of the judiciary, which it sees as part of efforts by Prime Minister Tayyip Erdogan to snuff out a corruption scandal.
Hours after the law was enacted late on Thursday, Justice Minister Bekir Bozdag appointed at least nine new senior members of the judiciary. The opposition Republican People's Party (CHP) said the law contained many violations of the constitution, and appealed to the Constitutional Court to repeal it.
Voice recordings posted on YouTube this week purporting to be Erdogan discussing financial matters with his son have piled pressure on him as he battles graft allegations, which pose one of the biggest challenges of his 11-year rule.
Erdogan has said the recordings are a "fabricated montage" and has accused U.S.-based Islamic cleric Fethullah Gulen, whose network of followers is believed to have built extensive influence in the police and judiciary over decades, of contriving the corruption scandal to try to unseat him.
The new law gives the government more control over the High Council of Judges and Prosecutors (HSYK), which makes top judicial appointments.
After a preliminary review, the Constitutional Court late on Friday asked the CHP to remedy technical errors in its paperwork and resubmit the appeal, NTV news channel reported and cited party officials as saying they would do so.
Erdogan had already responded to the graft investigation by dismissing or reassigning thousands of police officers and hundreds of judges and prosecutors, in what his aides acknowledge is a drive to wipe out Gulen's influence.
"With this law, the HSYK comes under the orders of the justice minister," Akif Hamzacebi, a senior deputy of the Republican People's Party (CHP), told reporters.
"This is clearly in violation of the principles of separation of powers and the independence of courts," he said, after filing the party's appeal.
SUSPECTS ALL RELEASED
The corruption scandal, which Erdogan has described as an attempted "judicial coup" ahead of elections this year, erupted on Dec. 17 with the arrest of dozens of bureaucrats and businessmen close to him, as well as three ministers' sons.
Prosecutors decided on Friday to release the two remaining ministers' sons and an Iranian gold dealer arrested that day, the Dogan news agency said, which will mean none of those originally detained two months ago are still being held.
The law on the judiciary is among several the government is pushing through parliament before local elections on March 30. It has already tightened control of the Internet and is seeking greater powers for the state intelligence agency MIT.
Turkey has been seeking membership of the European Union for decades, and the moves have raised concerns in Brussels that it is shifting away from EU norms.
The government says they are necessary to rescue judicial independence from Gulen's influence, to protect individual privacy online from the sort of recordings appearing on YouTube and to give its spy agency greater power to guard its citizens.
Gulen has repeatedly denied seeking to pull the levers of state power.
President Abdullah Gul, who approved the judiciary law on Wednesday, has said his objections secured last-minute changes to the bills addressing some of the concerns. But the opposition still disputes their legality.
Hamzacebi called on the Constitutional Court to suspend the implementation of the HSYK law to prevent staff being removed from their posts, as envisaged by the legislation.
Around 1,000 unelected staff, including its secretary-general, inspectors, audit judges and administrative staff, could lose their jobs or be reassigned as a result of the law, according to media reports.
Bozdag appointed five new deputy general secretaries, a new head of the HSYK's supervisory board and three supervisory board members on Friday. He also named a new head of the Justice Academy, where members of the judiciary receive training. (Writing by Daren Butler; Editing by Nick Tattersall and Alistair Lyon)