Health minister Nadine Dorries and two other Tory MPs have been ordered to “check the validity” of social media posts before sharing them.
Party bosses spoke to the MPs after they retweeted false allegations about Labour leader Sir Keir Starmer.
Sir Keir said he was satisfied with the actions taken by the party and the MPs, who have deleted the tweets.
“There are more important things in the world to concentrate on than a doctored video of me,” he added.
A Downing Street spokesman said: “These tweets have rightly been deleted.
“The MPs involved have been spoken to by the Whips’ Office and reminded of their responsibility to check the validity of information before they post on social media sites.”
As director of public prosecutions between 2008 and 2013, Sir Keir was head of the Crown Prosecution Service, the body that decides whether or not to prosecute someone accused of a crime.