The British Foreign Office on Sunday expressed its concern over the detention of former Ukrainian prime minister Yulia Tymoshenko who is on trial on the charges of the abuse of office during her term.

"I was very concerned to learn of the detention of the Ukrainian opposition politician, Yulia Tymoshenko, on 5 August," Foreign Office Minister Alistair Burt said in a statement.

The Pechyorsky Court of Kiev satisfied on Friday a request by a prosecutor to arrest Tymoshenko, who has been prosecuted for signing a 2009 gas contract with Russia, citing repeated violations of court order by the defendant.

"With our EU and international partners, the United Kingdom will continue to monitor closely the trial of Ms Tymoshenko and the cases against a number of her former ministers and officials," Burt said.

Kiev has accused Tymoshenko, currently Ukraine's opposition leader, of signing the gas deal, which was disadvantageous to the country, without approval from her government. Tymoshenko has dismissed the charges as "politically motivated," saying she is being targeted for opposing President Viktor Yanukovych, who narrowly beat her in the presidential election in February 2010.

"I urge the Ukrainian authorities to adhere to the highest democratic standards, including respect for human rights, the rule of law and an independent, transparent and fair judicial process. These are prerequisites for its closer integration with the European Union," Burt said.

Human right groups, including Washington-based Freedom House, have denounced Tymoshenko's arrest.