BUCHAREST - Romania's top court on Monday sentenced former Prime Minister Adrian Nastase to four years in jail for taking bribes, one of a handful of convictions in a poor country under pressure from the European Union to crack down on high level crime.

Former Prime Minister Adrian Nastase (C) arrives at Rahova prison after he was sentenced by Rmania's top court to four years in jail for taking bribes, in Bucharest, January 6, 2014. [Photo/Agencies]

The sentence will send Nastase back to prison just months after he finished serving a previous term, also on corruption charges. The 63-year-old leftist politician has repeatedly denied any wrongdoing and said the cases against him were all politically motivated.

Nastase is the first premier to be put behind bars since the collapse of communism in 1989. His lawyer told a local TV station that the former leader had agreed to give himself up to the police. Nastase did not speak to the media after the verdict, but local media footage later showed him in a car with his son going to the police station.

The EU has repeatedly raised concerns about a failure to tackle high level graft in Romania and Bulgaria, the bloc's two poorest members which have been blocked from joining the passport-free Schengen zone over the issue since their entry.

Romania once again came under scrutiny late last year after its lower house of parliament voted to increase the immunity of MPs against graft charges. The bill drew criticism from some western embassies and the president.

Nastase's conviction will not be a game-changer in regard to Romania's entry into the Schengen zone, said Cristian Patrasconiu, a Bucharest-based political analyst.

"But it is a very positive development towards achieving this goal, as the judiciary is now perceived as stepping up its efforts to rein in high-level corruption," he said.

Nastase had been freed from prison in March 2013 after serving nine months of a two-year term for corruption. The court on Monday also gave his wife Dana a three-year suspended jail sentence for her complicity in taking bribes.

Nastase's case dates back to 2006 when prosecutors indicted him and his wife in a landmark probe, charging Nastase with taking bribes worth 630,000 euros ($859,500).

Nastase was accused of using his position in 2002-2004 to obtain gifts from an official at a government building works watchdog in return for helping that woman keep her job.

Together with his wife, Nastase was also accused of ordering officials to violate customs regulations in order to bring construction materials and household goods from China to furnish his houses in Bucharest and a holiday retreat.

Prime minister in 2000-2004 and a mentor to the current premier Victor Ponta of the ruling Social Democrats, Nastase shot himself in a suicide attempt in June 2012 when police came to take him away to start his first sentence. He was not seriously injured.

The European Union, which Romania joined in 2007, has its justice system under special monitoring and has repeatedly urged it to get tough on officials suspected of abuse. ($1 = 0.7330 euros)