Madonna's permanent adoption of David Banda has hit problems after Malawian officials cancelled their visit to Britain.
Malawi's Minister of Women and Child Development, Kate Kainja, has reportedly banned Penstone Kilembe from visiting the pop superstar and her husband Guy Ritchie to assess their suitability to adopt the two-year-old.
Kainja has accused Kilembe of asking Madonna to give him money and pay for his flight to London without government approval, according to a weekly Malawian newspaper.
Kilembe denied he obtained money from the star and claims canceling the visit could threaten Madonna's chances of keeping David, saying: "What this means is that the whole adoption process may crumble and David could be sent back to his village."
Kilembe was due to visit Madonna and her family at her London home twice this year.
The Malawi high court was relying on his testimony to make a decision on whether Madonna's adoption should be formalized in a hearing next year.
Malawian officials claim they have selected another representative to conduct the assessment.
A minister said: "We have already contacted Madonna to inform her that someone else and not Kilembe will come to asses her, because we feel Mr. Kilembe personalized the whole issue."
However, as Kilembe was appointed by the high court, some sources believe he is the only one who can report his findings to the hearing.
Justin Dzonzi, a lawyer who led a 65-member human rights group in challenging Madonna's adoption, said: "Kate Kainja cannot change what the court set by having another person do the assessment. The court will not listen to anyone else apart from the one it appointed."
David has been living with Madonna since he left Malawi last October. Madonna and Guy were preparing to be quizzed on a series of "sensitive questions" during the official's five-day stay planned for this month.
The couple's parenting skills with their seven-year-old son Rocco and Madonna's 10-year-old daughter Lourdes from a previous relationship were also set to be assessed.