President Donald Trump is reportedly poised to tap New York commercial litigator Marc Kasowitz to lead his personal legal team, amid probes into his campaign's alleged contacts with Russia.

Far from an established, Washington DC white-collar figure, Kasowitz (pictured) is best known for handling a mix of complex, high stakes civil disputes in New York's state courts, particularly involving financial institutions. He and his firm, Kasowitz Benson Torres, brought billions of dollars in claims against Wall Street banks in the wake of the subprime crisis.

But Kasowitz has also been a loyal lawyer for Trump and his interests for close to two decades, in matters ranging from defamation to debt restructuring for Atlantic City casinos. Former Kasowitz Benson name partner David Friedman, a bankruptcy lawyer who was appointed US ambassador to Israel this year, was also a longtime Trump adviser.

Former Democratic senator Joseph Lieberman, who is reportedly a frontrunner to replace James Comey as FBI director, is a senior counsel with the Kasowitz firm.

Before Fox Business News and ABC News first reported Trump's selection of Kasowitz on Tuesday evening, citing unnamed sources, The Washington Post had identified him as one of four lawyers under consideration for the job. The others were Robert Giuffra of Sullivan & Cromwell (a fierce adversary of Kasowitz in financial crisis litigation); appellate lawyer Theodore Olson of Gibson, Dunn & Crutcher; and Washington criminal defense lawyer Reid Weingarten of Steptoe & Johnson.

It's not clear whether some of those lawyers or others could join a team of outside Trump lawyers under Kasowitz's direction. A larger team would appear necessary, however, especially given Kasowitz's relative lack of experience with white-collar matters and political investigations. As the president's outside lawyer, Kasowitz would have a separate mandate and responsibilities from White House Counsel Donald McGahn II.

The legal pressures facing Trump reached a new level of intensity during the past few days, after the president fired James Comey and then suggested his decision was related to an FBI investigation into his campaign's ties to Russia, which intelligence officials have accused of attempting to influence the election in Trump's favour. Comey's predecessor at the FBI, Robert Mueller, is expected to delve deeply into the activities of the campaign as special counsel, as are congressional investigators.

Kasowitz and his partners' previous work for Trump has included defending fraud claims against Trump University; bringing a defamation case against former Times business reporter Timothy O'Brien and publisher Time Warner Book Group; helping to restructure $1.3bn (£1bn) in casino debt; representing Trump and his daughter Ivanka against a casino takeover bid by Carl Icahn; and fighting media attempts to unseal divorce papers between Trump and his ex-wife Ivana.

Kasowitz also squared off in a very public spat with The New York Times in October, after the Times reported that Trump had sexually assaulted two women and the then-candidate threatened to sue.