In a statement issued on Monday, the lawyers said Karua was being held at Entebbe International Airport without access to her legal team, family members or colleagues and faced deportation to Kenya after arriving in Uganda to attend court proceedings involving Erias Lukwago and to support the defence of Besigye and co-accused Hajj Obeid Lutale.
The defence team described the detention as an attack on the administration of justice and alleged that the move was intended to weaken legal representation for opposition figures facing prosecution.
According to the statement, Karua's detention follows a series of public remarks by Muhoozi Kainerugaba that the lawyers say signalled an impending crackdown on opposition politicians and their legal representatives.
The lawyers cited social media posts attributed to Gen. Kainerugaba in which he warned of further arrests under what he termed a "Rectification Campaign" and made comments regarding lawyers involved in ongoing legal disputes.
"The purpose is unmistakable," the defence team said. "This action is designed to strip the defence team of one of its leaders, deprive Erias Lukwago of support during his bail proceedings, and intimidate advocates representing accused persons."
The team further alleged that Karua's detention violated constitutional guarantees relating to personal liberty, fair hearing and access to legal counsel, as well as regional and international legal obligations governing the treatment of foreign nationals.
They also claimed the move breached provisions of the East African Community Treaty and the Vienna Convention on Consular Relations by denying Karua access to legal representation and Kenyan diplomatic officials.
The lawyers demanded Karua's immediate release, unrestricted access to her lawyers and family, and the suspension of any deportation process until reasons are formally provided and legal avenues for challenging the decision are exhausted.
They also called on the Uganda Law Society, the Law Society of Kenya, the East Africa Law Society, diplomatic missions and international human rights organisations to intervene.
The incident adds to growing political tensions surrounding the prosecution of Besigye and recent legal proceedings involving Lukwago, with the defence team warning that the detention of Karua represents a broader effort to interfere with legal representation in high-profile opposition cases.
By Monday afternoon, there had been no immediate response from Ugandan authorities to the allegations contained in the statement.