Archbishop Thomas Becket had been murdered in the cathedral just a few years earlier on the orders of King Henry II. Becket was made a saint in 1173.
Dr Wells believes the timing of the great fire is too much of a coincidence. "The fire opened up a space for the construction of an elaborate crypt for pilgrims wanting to venerate the newly created St Thomas Becket.
"It is circumstantial but it fits very nicely into dates. This was a way to give them this beautiful elaborate place (for their) new saint."
Dr Wells, from York University, says written accounts of the fire provide additional evidence. She regards the description in the Chronicle of Gervase of Canterbury as being suspiciously neat, as if he was trying to divert attention from the possibility of arson.
"The fire occurred, allegedly, or so Gervase tells us from a few timber framed houses which were on the border of the monastery. And supposedly the wind blows over.
"It's all very 'fitting', I suppose is the word. And I'm looking at other evidence to see if that ties in nicely and does (the theory of arson) work."
Dr Wells argues the fire and subsequent building of the new crypt may have been part of rivalry between the cathedrals of Canterbury and Durham. At the time, Durham was the top destination for pilgrims with relics of England's most venerated saint, St Cuthbert.
But the murder of Archbishop Becket created a new reason for visiting Canterbury to pray at the place where he died. According to the historian's theory, the new crypt provided a resting place for the martyred saint and challenged Durham cathedral's pre-eminence.
"Durham was number one at that point, pilgrims were travelling there. (Canterbury) now had Becket. He was a martyred Archbishop. They thought they could take that crown. We can now have the number one saint.
"I think there are some legs in the fact that this could have been arson. At least that there was some sort of fire started. It is a little bit too easy, a little bit too wonderful that they managed to do this at this time."
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