The Electoral Commission is duty bound to investigate claims that the Nationalist Party's media company issued "false invoices" to cover payments meant as a donation to the party, Owen Bonnici said.
The Justice Minister made the appeal at a press conference at Labour headquarters as the party sustained its pressure on the Opposition leader to come clean on the matter.
"The Electoral Commission has all tools to investigate this breach of law and take all legal steps," Dr Bonnici said.
The case refers to claims by the db Group it had been asked by the PN's "top officials" to cover the wages of its CEO and general secretary. This was done through invoices issued every month by the PN's media company.
PN leader Simon Busuttil has denied this claims insisting the arrangement between db and Media.link was of a commercial nature for services rendered. The db Group insists it never took any advertising to justify the €70,800 it paid Media.link last year as part of this arrangement.
Labour MP Silvio Schembri challenged the Opposition leader to publish the invoices and give tangible proof of the services they refer to.
When asked whether the law on party financing should be changed to include scrutiny of the parties' commercial operations as well, Dr Bonnici insisted this was not necessary.
"This is not a loophole since the Electoral Commission is still empowered to investigate if the parties use their companies as financing vehicles for donations as was this case," he insisted.
Under the party financing law political parties are obliged to give the commission a list of donations but this excludes commercial contracts entered into by their media companies.
'PN is in nobody's pocket'
Meanwhile, the PN said it had no problem with the Electoral Commission probing the party's financials.
"The PN has nothing to hide and it's in nobody's pocket. The PN registered itself with the Electoral Commission and presented all documents requested at law."
On the other hand, the Labour Party is breaking the law on three fronts: it still is not registered with the Electoral Commission, it presented no details about donors, while top party officials and media presenters were being paid by people's taxes, the PN charged.
Prime Minister Joseph Muscat should declare whether his party is involved in fraud or money laundering.