21st Century Fox's proposed takeover of Sky has been referred to both Ofcom and the Competition and Markets Authority.
The regulators will investigate whether the Murdoch family are “fit and proper” owners following the phone-hacking scandal.
Culture secretary Karen Bradley has asked for Ofcom to report back by 16 May.
Sky agreed to sell the remaining 61 per cent of its business not owned by Fox late last year.
Ofcom will look investigate concerns over media plurality and Fox’s intentions to maintain broadcasting standards.
The proposed deal is also subject to European regulator clearance.