A human rights lawyer has been abducted in Kenya along with his client and a taxi driver after a court hearing in the capital.

Willie Kimani, a lawyer working for human rights and law enforcement organisation International Justice Mission (IJM), had been defending 24-year-old Josephat Mwende against "false claims" involving a police officer, IJM said.

The two went missing along with taxi driver Joseph Muiruir on June 23 after leaving a court in Mavoko around 1pm.

Eric Ha, general counsel at IJM, told Christian Today that Mwenda had filed a complaint against a police officer who allegedly shot him during an "improper arrest" last year.

"The police charged our client with what we believe were false charges related to drug possession and possession of a weapon," Ha said, which lead to Mwenda's arrest. "It was in the context of that case that they were attending the hearing [on June 23]."

Campaigners are concerned that corruption in the Kenyan judicial system resulted in the men's abduction.

According to the New York Times, after the men disappeared, Mwenda's wife says she received a call from an individual who claimed to have passed by a metal container on a police base in which at least two men were shouting.

They allegedly threw a piece of paper from the window asking him to call Mwenda's wife. When authorities visited the base that evening, however, the men were nowhere to be found and police denied seeing them.

IJM's vice president of investigations and law enforcement development, Mark Clookie, confirmed to Christian Today that "a note was passed" but was unable to speak further regarding the incident. "We're still in the midst of tracking down all the leads of who was present, who was responsible for passing the note, so we'd prefer not to get into that at this time," he said.

The taxi the three men had been travelling in was found abandoned in a village on Saturday.

In a statement, IJM said it is collaborating with Kenyan local and national law enforcement officials who are leading an ongoing investigation into the disappearance, and Clookie was adament that authorities on the ground have been cooperative.

"Kenya, like too many countries around the world, from time to time experiences corruption," he said. "We're there at the invitation of the Kenyan government to help pursue cases, and police corruption and abuse of power. That's why we're there." 

IJM crisis response teams are working both on the ground in Nairobi and in Washington, DC to locate the men and support their families.

The organisation, which has a biblical foundation, is also asking supporters to tweet the Kenyan ambassador in their country to alert them to the situation and urge them to help, using the hashtag #JusticeinKenya.

IJM's field office director in Nairobi, attorney Claire Wilkinson, said of the men's disappearence: "We are heartbroken by this horrific crime and are doing everything we can to locate these men and support the families of the victims.

"Our organization condemns this crime and remains committed to our mission of protecting the poor from violence and strengthening the justice system. Alongside local officials, we will pursue this case to justice."

"We're hoping for the best, obviously," Clookie told Christian Today. "We're continuing at a pace that would lead towards a rescue, that's our ultimate goal."