The laptop was found in a bin outside the flat in the Brussels district of Schaerbeek, which investigators say was used by the Brussels Airport suicide bombers, Belgian business dailywrote.
The bombs at the airport and another bombing on the Brussels metro car on March 22 killed 35 people, including three suspected attackers.
Belgium’s federal prosecutors declined to comment on the report, which also appeared in French-language newspaper
A spokesman for the Belgian Prime Minister was not immediately available for comment.
Meanwhile, around 20 Islamic State followers were arrested in Moscow trying to recruit new fighters for the group, Russia’s RIA news agency cited a security source as saying.
“During a joint operation of the FSB (Federal Security Service) and the police, around 20 people suspected of connections to ISIS (Islamic State) were arrested,” RIA quoted the source as saying. The FSB could not immediately be reached for comment; the police declined to discuss the matter.
“According to preliminary information, they were searching for and recruiting new members in Moscow,” RIA said, citing the source.
RIA said the majority of those arrested were citizens of the former Soviet republic of Uzbekistan. They had fake documents, including false Turkish driving licenses, it said. Russia is helping the Syrian army fight IS.