Director of Public Prosecutions John Champion, SC, had appealed against the men's jail terms, saying they were manifestly inadequate and the Court of Appeal on Monday agreed.

The girl had been drunk outside a railway station when the two men offered her a lift, before later driving her to the factory where they took it in turns to rape her during the night and into the morning.

Daniel Miftode, 27, formerly of Pakenham, was initially jailed for six years and nine months with a minimum of four years and three months after a County Court jury found him guilty of 10 counts of rape.

Ross Jurj, 29, formerly of Berwick, was jailed for five years and five months with a non-parole period of three years and seven months after he was found guilty of five counts of rape and one charge of sexual penetration of a child under 16.

Court of Appeal president Justice Chris Maxwell and Justices Robert Redlich and David Beach upheld the DPP's appeal on Monday and re-sentenced Miftode (DM) to 12 years and two months' jail with a minimum of eight years and nine months.

Jurj (RSJ) was re-sentenced to nine years and six months' jail with a minimum of six years and six months.

"There are, in our view, several features of the case which make it particularly grave," the appeal judges said.

"The first - and this applies to both, although more so in DM's case - is the prolonged nature of the offending and the repetition of acts of rape.

"The second is that, for so long as RSJ was present, each acted with the support and encouragement (express or implied) of the other.

"This feature heightens the men's culpability - offending in company is both more vicious and more cowardly - and underlines how powerless the victim would have felt."

The appeal judges said the fact the men had ignored the girl's obvious distress and her pleas for them to stop "underlines the humiliation these men inflicted on their victim".

"They treated her not as a person deserving of respect but as a chattel, a thing to be used for their sexual gratification in whatever way it suited them.

"In our view, the prolongation and repetition make this offending especially serious.

"Even at the beginning, this was not 'spur of the moment' offending.

"On the contrary, the offenders first took T (the girl) to a cafe to buy her a soft drink, before driving her to the factory. Throughout that period, they were doubtless forming - if they had not already formed - the intention of having sex with T.

"There was plenty of time for them to reconsider and drop her safely somewhere. This was offending calmly  and purposefully embarked upon. Any expectation that T might be a consenting participant was wholly irrelevant since ... both men knew that she was under 16."

The offences took place in April, 2009. The pair were charged in 2011 and a jury at their first trial in 2012 deliberated for six days but could not reach a verdict.

A second jury in 2013 was discharged for other reasons after a 15 day trial, as was a third jury for technical reasons, before Miftode and Jurj were found guilty in March 2015.