can an external recruitment agency still ask for my current salary

An external agency may not ask for it either

Yes, the prohibition also applies to an external recruitment agency. Article 5 of Directive (EU) 2023/970 is directed at "employers", but the prohibition on asking about remuneration in current or previous employment relationships is intended to prevent an existing pay gap from being carried over to the next job — and that effect is exactly the same whether the question is asked by the employer itself or by an agency that recruits and selects on behalf of that employer. An agency that handles intake questions, screening or initial interviews acts in that role as an extension of the employer, and the protection of the applicant would have a loophole if that question were allowed to be asked through an intermediary.

In practice, this means that a candidate's salary should not be part of the intake interview with a recruiter, not even as "just an indication for the match". Agencies that use salary history to pre-select candidates are doing exactly what the prohibition seeks to prevent. This is separate from the question of what a candidate may ask: can a candidate ask about the compensation level before the interview about the position itself, because that question is directed at the employer and not the other way around. The timing of when the salary level can be discussed is also fixed in the phase after the job posting — see can I still negotiate the salary after the job posting — and this does not change because an agency is between employer and candidate.

The basis: Article 5 of the Directive

Article 5 of Directive (EU) 2023/970 prohibits asking about remuneration in current or previous employment relationships; the text refers to employers, and an external agency carrying out recruitment and selection tasks on behalf of an employer falls within that same scope because it acts in that capacity. For the precise definition and any exceptions, the text of the Directive itself is the first source to consult.