Malawi's chief social welfare official has paid a visit to Madonna's London home, part of a long-delayed assessment into whether the pop idol can adopt a little boy from the African country.

Simon Chisale was spotted leaving the singer's home Wednesday afternoon clutching a blue binder, but he refused to comment and attempted to hide his face when approached by The Associated Press.

Madonna's New York-based spokeswoman did not immediately reply to an e-mail requesting comment.

Chisale is filing a report on the suitability of Madonna and filmmaker-husband Guy Ritchie as adoptive parents for toddler David Banda, who was plucked from a Malawian orphanage during a visit there by Madonna last autumn.

In October, Madonna and Ritchie were granted temporary custody of David, then 13 months old, but that could be revoked if it's found that David is being treated differently from their other children or if the toddler's rights are being violated in any way.

The assessment originally was due to have been made by Penston Kilembe, the director of Malawi's Child Welfare Services. However, he was removed from the case following allegations that he had solicited money from the singer for his trip to London.

On Monday, Adrina Mchiela, a top civil servant in the ministry responsible for child welfare, said Madonna was paying tuition and living expenses for a ministry staffer studying in Britain, and had offered to sponsor others.

The allegations renewed the concern that the singer had used her wealth and celebrity status to manipulate the adoption process.

Kilembe has denied any wrongdoing, and in a statement earlier this week Madonna said there had been no interference with government officials.