Fast-growing Lenovo, a Chinese PC maker keen to strengthen its hand in mobile devices, is reportedly preparing a bid for Ontario-based BlackBerry even though previous advances by the Chinese firm were given short shrift by the Canadian government on security grounds.

Citing an unnamed source familiar with the matter, Benzinga.com, a news agency, said Lenovo was expected to make a bid for BlackBerry worth $15 per share – significantly up on the Canadian firm’s sub-$10 share price at the close of Friday’s trading – and may be willing to go as high as $18 per share.

This is not the first time Lenovo has been linked with BlackBerry, but the problems it faced in previous takeover attempts have not gone away.

A big stumbling block is that BlackBerry is a supplier to Canadian and US governments – as well as military agencies – and so is responsible for guarding sensitive data travelling across its secure network. According to Canada’s The Globe and Mail, BlackBerry devices account for around 80 per cent of all smartphones handed out by the US defence department. Authorities on both sides of the border are unlikely to hand control of that network over to a Chinese company.

And John Chen, BlackBerry’s chief executive (who is engineering something of a recovery for the smartphone maker) has been notably keen to emphasise the firm’s Canadian roots.

It’s also not clear how Lenovo’s upcoming $3 billion takeover of Motorola from Google would sit with a BlackBerry acquisition.

An improved financial position makes it less likely too that BlackBerry would rush into any deal with Lenovo, even if the regulatory concerns could be dealt with. When rumours were rife of various suitors lining up to make a BlackBerry bid last year, the Canadian firm was struggling for survival. Chen said last month, however, that he was confident BlackBerry would achieve breakeven cash flow by the end of its 2015 fiscal year.