In Portugal and in Brazil, the past participle should not have enclisis; in Portugal, it should neither have proclisis; then, the participle has no clitic pronoun. Basically, sentences as “Ele tem me visto” and “Tem pagado-me” are wrong.
But something can both be wrong and be used — figures of speech are actually intentional grammatical errors. In the Corpus do Português, there are three corpora. Searching on the three by an example of a regular participle with an eclitic pronoun (e.g., eu tenho pagado-te), I found only a few examples. Most examples could be only an error, since the past participle and the gerund have a lot in common in Portuguese, and their writings are similar enough; for example, here, with perhaps tornado-se instead of tornando-se.
But some even fewer examples were probably not a mistake, as on here. These websites also had a more colloquial language.
Therefore, the forms «tem-me pagado» and «ele não me tem pagado» seem to be the most common. The rest, that is «tem me pagado»/«tem me-pagado» and «tem pagado-me», seem to be exceptional.