The written statement and by pleading the ignorance having no knowledge about of facts would amount to an admission.

...Bearing in mind that O. VIII, R. 5, C. P C. provides that every allegation of fact in the plaint, if not denied specifically or by necessary implication or stated to be not admitted in the pleading of the defendant shall be taken to be admitted to say that a defendant has no knowledge of a fact pleaded by the plaintiff is not tantamount to a denial of the existence of that fact, not even an implied denial...