Michael Gallagher, who lost his son Aidan in the Real IRA atrocity, has questioned why it has taken 12 years for RIRA man Campbell to face the courts in the Baltic state considering the seriousness of the charges against him.
And he revealed his fears that the notorious dissident figure will strike a deal with authorities if found guilty to serve his time in Portlaoise Prison in Ireland.
The Omagh bomb suspect was extradited to Lithuania on Tuesday where he is wanted on gunrunning charges.
"It is unbelievable that it has taken all these years to extradite someone to another EU country who is wanted in connection with terrorist activity.
"I have read of cases when people have been arrested on a European Arrest Warrant and they have been extradited within days, hours even. Like The Monk. Why has this taken so long for him (Campbell), why did he get special treatment?," Mr Gallagher told the
"What I want to know now if has there been a deal done, where he will be repatriated in Ireland if he is convicted?
"He should serve his time in Lithuania, that is where he is suspected of committing the crimes he has been charged with."
Campbell could face up to 20 years behind bars if the courts find him guilty.
"I hope he is found guilty and gets the full 20 years, he got away with Omagh and we all know he was the man behind that.
"If I went to Colombia and got caught trying to transport drugs then I should serve my sentence in a prison in that country. Liam Campbell has been extradited to a country within the EU, Lithuania is not Iran or North Korea so I find the talk of infringing human rights ridiculous."
The south Armagh man was found liable by a civil court for the 1998 Omagh bomb atrocity that killed 31 innocents. He fought three extradition attempts on the grounds that it was against his human rights.
"He was found liable in a civil action for Omagh but after that he carried on with his life as if nothing happened. If he is found guilty in Lithuania then he is guilty of trying to bring guns and explosives into Ireland to kill and maim Irish people, people like my son," Mr Gallagher said.
Aidan was 21 when he was brutally taken from his loved ones.
The coat of the self-employed mechanic still hangs in the family garage where he worked. It gives comfort to the grieving and campaigning family.
Speaking at the time of the 20th anniversary, Michael said: "I'm sure the ghost is still there."
Michael and the other Omagh bombing families have never given up on achieving justice. If Campbell gets banged up it would bring some solace.
"The law has finally caught up with him. As the saying goes, long run the fox. I just hope the Lituanians can push this and I am grateful to them because we might just get some justice.
"Liam Campbell has been free long enough, he has to be punished and I hope this sends a hard message to other dissidents that you just can't get away with killing and bombing innocent people of this country," he added.
Campbell has been charged of trying to acquire weapons for the Real IRA. His brother Michael was previously convicted of weapons offences in Lithuania before being freed on appeal.
Liam (59), with an address in Upper Faughart in Co Louth, was arrested on Monday night by gardaí who handed him over to the Lithuanian authorities at Dublin Airport on Tuesday. He is expected to appear in court in the country's capital, Vilnius, in the next few days.
Campbell had fought the European Extradition Warrant and lodged several appeals to the higher courts challenging the process. The legal battle, which has been going on for more than a decade, was exhausted earlier this year.
Campbell previously spent four years in custody in Northern Ireland during the second attempt to extradite him, but was released when his legal team successfully argued that to surrender him would be a breach of his human rights.
A separate warrant was then issued in the Republic which was eventually granted last week.
The Sunday World revealed last week that Campbell will be held in a prison in Lithuania where human rights and torture are concerns.
It is believed he has already been transferred to Kaunas Remand Prison while he awaits trial for offences including terrorism, possession of weapons and smuggling.
Lithuanian media sources also revealed last week that Campbell would find it hard to adjust to life behind bars in any institution in the country where the Committee Against Torture found that the state continues to infringe on the rights of prisoners, and violence from both guards and other inmates is rife.