The European Parliament on Tuesday announced a probe into a Latvian lawmaker accused in an investigative report of spying for Moscow over the past two decades.

According to the Russian-language newspaper The Insider -- an independent investigative outlet based in Latvia -- Tatjana Zdanoka, who joined the European legislature in 2004, began collaborating with Russia's FSB security services the very next year.

The extensive report, based on leaked emails between Zdanoka and her alleged Russian handlers, exposes how she acted as a "trusted asset of Russian intelligence", providing "explicit, detailed reports" on her work as a European legislator.

The investigation carried out jointly with several other media, including the Swedish newspaper Expressen and an Estonian website, says Zdanoka was "openly advocating" for Moscow in both Brussels and Riga throughout her tenure.

Leaked emails refer to in-person meetings in Moscow or Brussels between Zdanoka and a Russian handler, as well as requests for Russian funding for her political activities both in Latvia and Brussels.

European Parliament President Roberta Metsola "takes these allegations very seriously and is referring the case to the Advisory Committee on the Code of Conduct", Metsola's spokesperson said.

"This means that investigations within the European Parliament have been opened."

The question will also be on the agenda of a meeting on Wednesday between the parliament's political leaders.

- Ethics code -
"We take note that these allegations have been reported in the member state of the MEP already for some time," the parliament's press service said, adding: "All MEPs are subject to the same rules... regarding independence of the mandate or ethics."

The parliament's statement also referred to potential follow-up action by Zdanoka's home country, Latvia.

Questioned about the accusations against Zdanoka, the Kremlin's spokesman dismissed them as a politically motivated witchhunt and an echo of the anti-Communist fervour of the Cold War era.
"Do you remember McCarthyism in the United States?" asked Dmitry Peskov.
"How many people were arrested back then, thrown in jail after being accused of ties to Communists or the KGB? It's the same thing."

"We strongly condemn all of this," he added, saying the accusations flew in the face of Europe's "supposed democratic ideals".

The espionage allegations come just over a year after the European Parliament was rocked by the "Qatargate" corruption scandal, in which a number of European lawmakers stood accused of being paid off to promote the interests of Qatar and Morocco.