This brings the total number of open investigations into RT, formerly Russia Today, from seven to 11.
An Ofcom spokeswoman said the further investigations are looking into “the due impartiality of news and current affairs programmes broadcast” on the channel.
One of the new investigations is regarding a segment on current affairs programme Crosstalk, and the others will be assessing two news broadcasts, which aired across April and May.
Crosstalk is being assessed over a segment which focused on the dynamics of the ongoing Syrian conflict and the US foreign policy in Syria.
One of the news broadcasts is being assessed over its reporting of the Ukrainian government and its position on Nazism and the treatment of Roma Gypsies, while the other was focused on fracking in the UK and the reported treatment of anti-fracking activists by UK authorities.
The regulator will look into whether each of these three broadcasts, which aired across April and May, offered sufficient balance for viewers on each topic.
• READ MORE: Litvinenko widow urges Alex Salmond to quit RT
In April, Ofcom said that since the Salisbury nerve agent attack of former spy Sergei Skripal and his daughter, Yulia, it had “observed a significant increase in the number of programmes” on the channel that should be investigated.
“Until recently, TV Novosti’s overall compliance record has not been materially out of line with other broadcasters,” Ofcom said of the company that broadcasts RT.
“However, since the events in Salisbury, we have observed a significant increase in the number of programmes on the RT service that warrant investigation as potential breaches of the Ofcom Broadcasting Code.
“We will announce the outcome of these investigations as soon as possible.”
• READ MORE: Ruth Davidson calls for ban on RT ‘propaganda’Other programmes already under investigation include two broadcasts of a show called Sputnik, hosted by George Galloway.Ofcom also previously announced it would consider whether the TV channel should broadcast in the UK if Russian involvement was proven in the poisoning in Salisbury in March.The regulator previously said it had written to RT to explain that evidence of unlawful state interference would affect whether it was deemed “fit and proper” to hold a broadcasting licence.