Particulars of claim alleging harassment and defamation were struck out almost in their entirety where the claimant was unable to demonstrate reasonable grounds for bringing such claims against a company investigating his conduct in the course of clinical research.Applications to strike out and/or for summary judgment in relation to claims for harassment and defamation. The claimant ('S') was a psychiatrist with a particular interest in schizophrenia. As well as being a senior lecturer at the Institute of Psychiatry ('IOP'), he owned a private clinical research-based company called Psychmed Limited. In 1999 S agreed to carry out a comparative study into drugs for schizophrenia ('the COGS study') which was funded by a pharmaceutical company ('Sanofi') in the sum of ?175,000. In 2000 Sanofi became concerned about certain aspects of S's conduct and retained the third defendant ('MLI') to investigate its concerns. The first defendant and second defendant were respectively the chief executive and medical advisor of MLI who attended a meeting in March 2001 at IOP in order to find out more about the COGS study. S contended that at this meeting he was slandered in that words were spoken which had defamatory meanings, and further submitted that, by approaching IOP and a number of other third parties about his research work, the defendants had pursued a course of conduct against him that amounted to harassment. In consequence S sought general, aggravated and special damages for the damage caused to his research team and his reputation. The defendants applied to strike out S's claim under CPR Part 3.4 as disclosing no reasonable grounds; alternatively, for summary judgment under CPR Part 24 as having no reasonable prospect of success.HELD: (1) In relation to the application to strike out, the court had to assume that the facts were as alleged in the statement of case which was sought to be struck out. So far as the application for summary judgment was concerned, the correct approach to be taken was to consider whether, on the evidence taken at its highest, a jury could not properly come to a conclusion in favour of the party against whom summary judgment was sought (see Swain v Hillman (2001) 1 ALL ER 91 and Alexander v Arts Council of Wales & Anor (2001) EWCA Civ 514). (2) In light of the decision in Thomas v News Group Newspapers Limited & Anor (2001) EWCA Civ 1233, the principal questions to be asked in relation to striking out the harassment claim related to the quality of the acts said to constitute a course of conduct that amounted to harassment, namely: (a) whether S had established an arguable case that the defendants' conduct was unreasonable; and (b) whether the particulars of claim alleged more than that the defendants engaged in conduct which foreseeably caused distress to S. On the evidence S had failed to establish that the defendants' conduct had been unreasonable or oppressive. MLI was in the business of conducting investigations into misconduct in clinical research, which served the public interest by preventing damage to the health of patients. In furtherance of their legitimate motive and in order to carry out their investigations, it was necessary for MLI to meet with IOP and also to make enquiries of other funding organisations and pharmaceutical companies. It followed that the relevant part of S's particulars of claim would be struck out as disclosing no reasonable grounds. (3) With the exception of one paragraph, the particulars of malice would be struck out on the basis that they were equally consistent with the absence of malice and disclosed no reasonable grounds for having been brought (see Telnikoff v Matsuevitch (1991) 1 QB 102). S had failed to establish that the defendants were predominantly actuated by some motive other than that of making enquiries for the purposes of their investigation into the COGS study which they had been commissioned by Sanofi to make. However, as the allegation in that one paragraph was sustainable, summary judgment for the defendants in relation to the issue of malice was declined.Judgment accordingly.