Donald Trump's real estate company actively pursued plans for a commercial development in Moscow while he was running for president, Trump Organization lawyers said in documents reviewed and reported by US media Monday.

The involvement by the then-candidate in a proposed commercial property in Russia contradicts Trump's repeated declarations during the presidential campaign that he had no business ties to the country.

The deal, in which a Trump Tower-style edifice was planned for Moscow, reached the “letter of intent” stage, but ultimately was not finalised, the Trump Organization's chief counsel at the time, Michael Cohen, told ABC News in a statement.

“Certain documents in the production reference a proposal for 'Trump Tower Moscow,' which contemplated a private real estate development in Russia,” Cohen said.

The decision to pursue the proposal was “unrelated” to Trump's presidential campaign, Cohen said.

But he added that he personally told Trump about the proposal “on three occasions, including signing a non-binding letter of intent in 2015.”

According to ABC, the revelation came as Cohen's attorney provided several documents and emails to US congressional investigators.

The commercial proposal was first reported Monday by The Washington Post.

The newspaper detailed how a Russian-born real estate developer, Felix Sater, urged Trump to push the deal.

Sater also boasted of his ties to Vladimir Putin, saying he could get the Russian president to say “great things” about Trump, according to people briefed on the exchange.

“Our boy can become president of the USA and we can engineer it,” Sater wrote in a November 2015 email quoted by The New York Times.

“I will get all of Putin's team to buy in on this, I will manage this process.”

The reported exchanges form some of the strongest signals yet that Trump was connected ─ at least through his company ─ to Russia, a country that US intelligence leaders have concluded sought to sway the US presidential election in Trump's favor.

The US Justice Department and congressional committees are probing the extent of the ties and collusion, if any, between Trump's campaign and Russia.

Sater, according to the reports, said he had arranged the financing for the deal through Russia's VTB Bank, which was under US sanctions for its alleged involvement in Moscow's intervention in Ukraine.