Italy’s competition regulator has fined online review platform Trustpilot and its units 4 million euros ($4.6 million) for failing to adequately verify the authenticity of reviews and for misleading consumers about how their services work.

Shares fell 2.5% in early trade.

The fine, imposed on Monday, comes months after short seller Grizzly Research accused Trustpilot of creating fake profiles that gave negative reviews and then pressuring companies to pay for subscriptions - allegations which the company rejected.