Salim Mehajer's property empire is showing considerable strain, as investigations by the Herald reveal his companies have been unable to meet court-ordered payments, taken on unfavourable loans and sold-off undeveloped land.

One month since the administrator of Auburn council cost the controversial developer-politican an estimated $10 million by cancelling favourable planning decisions, one of his signature companies appears to have almost no cash on hand.

A Sydney court ordered Mr Mehajer's Sydney Project Group to pay a sign writing company $25,000 in costs for a crown design on one of his cranes more than three months ago. But it can be revealed that barely any money has been repaid since.

Fairfax Media has learned that Mr Mehajer's company twice missed the 28-day deadline imposed by the court for payment, forcing attempts to freeze money under court order.