The Varyag was meant to become the pride of the Soviet fleet
The rusting hulk of the Soviet-built carrier, the Varyag, was bought for $20m in 1998 by a company hoping to turn it into a floating casino anchored off Macau.
This week they suggested the 67,000-ton vessel could be allowed through after either being cut into pieces or provided with its own engine.
Smokescreen
"Since the straits are not going to get bigger this platform should get smaller," said Turkish Maritime Affairs Minister Ramazan Mirzaoglu.
Joop Timmermans of ITC responded: "We believe it is a political issue converted into a technical issue... apparently there are people who do not like to see China having another aircraft carrier."
Although the Varyag is officially destined to become an entertainment centre, with discos and a hotel as well as gaming facilities, some analysts believe this is just a smokescreen.
They argue that the current owners are no more than a front for the Chinese navy.
However, others say that the rusting Varyag - begun in 1985 - is no longer of any military value. They also find it hard to understand why China should feel obliged to act in a cloak-and-dagger fashion.
Helicopter on deck
Mr Timmermans said an unfinished aircraft carrier powered by a tug was more easily manoeuvrable than a big oil tanker, and that there was no good reason why it should be not allowed through the straits.
The Turkish authorities argue that, together with its tugs, the Varyag would be more than 550m long and would have difficulty making the 15 changes of course required to navigate the straits.
At its narrowest, the Bosphorus is just 672m wide, and simultaneously makes a 45-degree bend.
Mr Timmermans confirmed reports of a mysterious landing on the Varyag's flight deck last month by an unidentified helicopter.
Men jumped out and appeared to take a number of measurements before flying off, leaving behind a message chalked on the deck: "The French was here."
Payments
Mr Timmermans says he finds this episode less surprising than the fact that his tug has been "held hostage" in the Black Sea for so long.
"We are a small party caught in between two bigger parties - China and Turkey. That's the weirdest thing, that we've been held captive," he says.
He says the Varyag's owners have been paying ITC $8,500 per day, with some delays, but that the company is "very close" to giving up the contract, and taking some other unspecified action.
"If our Chinese contract party does not do something we have to do something," he says.
"Precisely what, I cannot say."