Aidan McAteer has had his jail sentence increased after he posted pictures on social media from prison.
McAteer was jailed for nine years after he knocked over and killed four-year-old Violet-Grace Youens in a stolen car before fleeing the country.
The 24-year-old, from Prescot, posted a snap on Instagram of a card reading “HMP Birthday Boy”.
It is believed the card was given to him by fellow inmates at HMP Liverpool. The post has been liked around 200 times.
McAteer was given extra time after the matter was brought to the attention of the Ministry of Justice (MoJ).
A spokesman for the MoJ declined to reveal how much time was added to McAteer’s sentence.
However, he added: “An investigation was carried out by the prison and the individual received additional time following an adjudication.
“It is a criminal offence to bring a mobile phone into prison, or transmit sounds or images from within a prison using a mobile phone.
“These offences carry a maximum penalty of two years in prison.
“We are stepping up measures to find and block illegal mobile phones, including a £2million investment in detection wands and legislation to block phones from being used in prisons.”
An investigation is also underway into Dean Brennan, 27, who was a passenger in the stolen car, and was jailed for six years.
He is alleged to have posted a picture of himself and fellow inmates on Snapchat with the caption “Jail life”.