Malawi government has been asked to follow the law in replacing Financial Intelligence Authority (FIA) director general Atuweni Juwayeyi Agbermodji whose contract expired.
Government has decided not to extend Atuweni's contract.
But British High Commissioner to Malawi Holly Tett and Human Rights Defenders Coalition (HRDC) described the outgoing FIA head as "professional."
According to Tett, the UK was "impressed" by Atuweni who worked effectively at FIA as a "dedicated and hardworking woman."
She said Atuweni demonstrated "quality of leadership"; saying good progress has been made in reducing Malawi's financial crimes risk.
Tett said the UK is looking forward to working with a new director general of FIA, but asked Malawi government to be transparent in selecting the new head as stated by the law.
Most appointments in Malawi government are made on political patronage or nepotism, critics say.
HRDC vice chairperson Gift Trapence accused government that it does not want officers like Atuweni "who are ethical and professional."