KIEV (Reuters) - Amnesty International urged Ukraine on Thursday to put an end to "shocking levels of mistreatment of detainees" by police, but Kiev said the rights group had exagerrated the problem.

"Beatings and torture continue unabated in Ukraine in spite of the new Criminal Procedure Code adopted by the government late last year," David Diaz-Jogeix, Amnesty's Europe and Central Asia deputy program director, said in a statement.

The London-based group cited cases of Ukrainians who it said had been beaten and given electric shocks by police but whose complaints had been dismissed by courts or state prosecutors.

Out of 114,474 complaints made to prosecutors about police treatment in 2012, only 1,750 were investigated and only 320 prosecution cases were opened against 438 police officers, it said.

Ukraine's interior ministry said it was ready to work with the group but denied claims that abuse was rampant.

"Their (Amnesty's) work is very important but sometimes they blow things out of proportion," ministry spokesman Volodymyr Polishchuk said.

A total of 77 criminal cases were launched against policemen last year for abuse, torture and battery, Polishchuk said.

Ukraine has long been criticized by the West over human rights and, in particular, for the prosecution of opposition politicians under the government of President Viktor Yanukovich.

Yanukovich's main political opponent, former prime minister Yulia Tymoshenko, was sentenced to seven years in prison on abuse-of-office charges in 2011 in a case seen by Western leaders as an example of selective justice.

(Reporting by Olzhas Auyezov; editing by Andrew Roche)