Britain's election watchdog has launched a probe into campaign spending by the pro-Brexit group, Leave EU, ahead of last year's historic poll.<br/><br/>The Electoral Commission said in London today that an initial assessment concluded that there were reasonable grounds to suspect that potential offences under the law may have occurred. The investigation will focus on whether the group had accepted "impermissible" donations and on whether it had fully completed its spending return.<br/><br/>The commission said in a statement that once the investigation is complete, the Commission will decide whether any breaches have occurred and, if so, what further action may be appropriate.<br/>'<br/>''''''''<br/>