Former New Mexico Gov. Bill Richardson plans to travel to Russia for talks to reach a deal with Brittney Griner (WNBA star) who is currently being held in detention. A source familiar with the matter told ABC News.

Richardson was also the U.S. ambassador at the United Nations and the energy secretary in Clinton's administration. He played a part in the April prisoner exchange that saw Russia free Trevor Reed, a former Marine from the United States, after almost two and a quarter years of captivity.

According to a source, he is likely to travel to Moscow within the next few weeks. The source requested anonymity due to the sensitive nature of the matter.

Russia repeatedly stated that it is interested in Griner being traded for Russians in U.S. jails. This new trip seems to be aimed at determining if Griner could benefit from a similar deal as the one that released Reed.

Richardson's office declined to confirm Richardson's possible visit and told ABC News that they were unable "to comment on this at the time."

"What I can tell you (and it is publicly known) is that both the Whelan-Griner families have asked us for assistance in releasing their loved ones," Mickey Bergman from the Richardson Center for Global Engagement told ABC News via email.

Richardson represents the Griner family, as well as the Whelan family, who was held by Russia for the past three-and-a-half years.

Griner, who is a two-time Olympic basketball gold medalist, was detained in Russia in February after being stopped at Moscow's Sheremetyevo Airport and accused by Russian authorities having vape cartridges containing cannabis oil in her luggage.

Griner said this week that she would plead guilty to these charges in a Moscow court. Griner claimed she brought the vape cartridges to Russia unintentionally and explained that she didn't mean to leave them in her bag.

Griner was "wrongfully Detained" by the Biden administration. American officials believe that Russia took Griner, along with Reed and Whelan, as bargaining chips to the U.S.

Rumours swirling that Richardson might travel to Russia are fueled by speculation about whether the U.S. would consider another prisoner swap in order to release Griner. Although the Biden administration stated that it was committed to negotiating Griner's freedom, it refused to comment on any trade.

When asked by ABC for comment, the White House National Security Council stated that it had been in touch with Richardson and appreciated his efforts. However, they declined to elaborate further.

"NSC leadership have been in touch with Bill Richardson. Adrienne Watson, spokesperson for NSC, stated that they appreciate Richardson's commitment to American citizens and are working with government channels to release Brittney or Paul.

Cherelle Griner, Griner's spouse, stated that she had asked Richardson's team for their assistance and would support a trip, if it were to take place.

Cherelle Griner stated that "we asked the Richardson Center for help" and was encouraged by the possibility of him going.

Richardson has a long track record of helping to free Americans wrongfully held overseas. Richardson has worked with the Richardson Center to help Americans who were imprisoned in North Korea and Iran.

He represented Trevor Reed's family, and his team spent months engaging in shuttle diplomacy to try to negotiate a deal that would free him.

Richardson flew to Moscow to try to convince Russia to trade on the eve Russia's invasion in Ukraine.

Richardson is not a representative of the White House. Reed approached Russia's government separately and the Biden administration to see if there was a possible deal. Then he relayed the information to both sides.

The White House's prisoner trade for Reed was, in the end, the same as Richardson had advocated for: the release of Konstantin Yaroshenko (a Russian pilot currently serving a U.S. sentence for drug smuggling).

Richardson encouraged the Biden administration since to make similar deals for Griner, Paul Whelan.

Karine Jean-Pierre, White House press secretary, stated that the White House was going to "do everything possible to bring Brittney Griner home safely and also to make sure that Paul Whelan is returned home." Jean-Pierre stated that Griner's guilty plea would not have any impact on negotiations for Griner's release.

Russian officials and state media have often floated the idea of trading Griner or Whelan to Viktor Bout, the Russian arms dealer. He is currently in a 25-year sentence for narcoterrorism and has been called "the Merchant of Death".

Trevor Reed and his family have asked the Biden administration for Bout to be exchanged if it would allow Whelan or Griner to be freed.

Reed spoke to ABC News this week and urged President Joe Biden not to stop doing more.

He told ABC News that he hoped President Biden and his Administration would do all they can to get Brittney and Paul out from Russia and that they would do it immediately. "Because every day they wait to make a decision, is one more day that Brittney and Paul are suffering," he said.